Crypto is not one the harder ones to get rid of. The Wiki article is just stating that not one agent will always get rid of it for 100% of those treated - in other words you might have to try different agents to eradicate. Rifaximin has been shown effective against this.
You could try a natural route first. Oil of oregano (enteric coated by NOW) with myrrh/goldenseal from Nature's Way, neem, garlic (fresh), Caprylic acid, monolauric acid, black cumin in different combinations may be effective. Homeopathy may offer another route.